Thread guide for sewing machines



Aug. 24, 1943. A. B. CLAYTON THREAD-GUIDE FOR SEWING MACHINES Filed March a, 1942 Patented Aug. 24, 1943 GUIDEFOR SEWENGMEAGHINES Andrew Clayton, Union, N. 3., assignor to The ISinger Manufacturing Company, Elizabeth,

N; J'., a corporation of New Jersey 'Appiication March 6, 1942;, Serial No. 433,539

, 'fifilaims.

" This invention. relates to thread-guides for sewing machines and it has as a primary object r to provide a tube-like thread-guide of substantial length which readily may have a. thread placed therein without projecting it lengthwise therethrough and which will effectively main tain control of the thread after it has been placed in the tube.

Another object of the invention is to provide an easy threading tube-like thread-guide of simple form which may be fitted within the upper face of the work-supporting plate of a sewing machine without the necessity of performing any complicated or expensive machining operations.

A further object of the invention is to provide a slotted tube-like thread-guide which may be fitted within the upper face of the work-supporting plate of a sewing machine and'into which the thread may be placed by a lateral movement of thethread, as for-example by stretching the thread lengthwise of the tube andmerely wiping the threadinto the tube by running one finger lengthwise of the tube, in pressure contact with the upper surface thereof.

These and other objects have been attained by the provision of a flat tubular thread-guide adapted to be fitted into a plain milling cut in the upper surface of the work-supporting plate of a sewing machine, said thread-guiding tube having in its upper wall a sinuous slot through which the thread may be passed sidewise into the tube. After the thread, which passes through fixed thread-eyes at opposite ends of the tube, has been passed into the tube the oppositely directed portions of the upper wall of the'tube, at opposite sides of the slot therein, overlie the thread and prevent it from being moved laterally out of the tube.

Drawing depicting a preferred embodiment of the invention has been annexed as a part of this disclosure and in such drawing:

Fig. 1 is a rear elevation, partly in section,

of a portion of a two-thread chain-stitch sewing machine having the improved thread-guide embedded in the work-supporting plate thereof to guide the looper thread.

Fig. 2 is a plan view of the machine illustrated in Fig, 1 with certain parts omitted or' the. Workasupporting plate of. the sewing machine} Fig. 4 is a. plan view of a sheet metal. blank fromrwhich the improved thread-guideis formed.

Referring. more specifically to the drawing the invention isdisclosed as embodied in a sewing machine comprisingaframe I affording a horizontally disposeda.work-supporting plate 2;, a standard 3 and. an overhangingnarm 4' which carries: atits free: end. a needle-bar supporting head,.not" shown. Located beneath the .worksupportingplate is a four-motion thread-carrying chain-stitch .looper. 5: which cooperates. with a threadecarrying needle (not shown) inthe formation of. stitches, and a thread take-up mechanismfll comprising a. rotary take-updisk 6 and fixed thread guides'l and 8.

My improved" thread-guide. for leading thread t to the thre'adtake-up T, from which it passes to the, looper. 5,". comprises. axflat metallic tube il-which, as shown most'clearly in Fig. 3,is embedded in a groove l0 milled into the upper face of the work-supporting plate 2. At the rear end of the thread-guiding tube, and recessed into the plate 2, is a fixed thread eye I I which directs the thread into the intake end of the tube. The tube is substantially rectangular in cross-section and is provided with a sinuous slot l2 through its upper wall. The tube 9 is preferably formed slightly wider than the groove Ii] and because of the slot l2 therein, the tube is resilient and may be slightly compressed to permit it to be forced into the groove. When the tube has been forced into the groove it is maintained therein by friction between the side walls of the tube and the vertical walls of the slot, thus eliminating the necessity of any other fastening means.

The thread i is adapted to be passed laterally through the slot I2 to the inside of the tube. This readily may be effected by stretching the thread lengthwise of the tube and wiping it through the slot by running one finger lengthwise of the tube in pressure contact with the upper surface thereof. When within the tube and tensioned as it normally is during a sewing operation the projecting convex portions a, b, c, d, e, of the upper wall of the tube overlie the thread and prevent it from accidentally escaping through the slot l2.

The tube 9, with its sinuous slot I2, is preferably formed from the serpentine sheet metal blank B shown in Fig. 4. This is efiected by folding the blank along imaginary longitudinal lines indicated graphically by dot-dash lines w, m, y and a. When the blank has been folded at w, :c,

y and a into the substantially rectangular tube as shown in Fig. 3' the convex marginal portions a, b, c, d, and e lie adjacent to but are spaced slightly from the complemental concave marginal portions 0,, b, c, d and e, respectively, thereby affording between them the sinuous slot After the tube 9 has been formed, the end 9 thereof may be shaped to conform to the curved opening 2 formed in the work-supporting plate 2 for the reception of the usual cover-plate not shown.

Having thus set forth the nature of the invention what I claim herein is:

1. In a sewing machine, thecombination with a frame having an external groove, of a threadguiding tube fitted within said groove and having a sinuous slot formed in one wall thereof for the lateral passage of a thread into the tube.

2. In a sewing machine, the combination with 3. In a sewing machine, the combination with a Work-supporting plate having a substantially rectangular groove formed in its upper surface, of a thread-guiding tube fitted within said groove with its upper wall substantially flush with the upper surface of said work-supporting plate, said tube being substantially rectangular in crosssection and having a sinuous slot formed in its upper. wall from one end of the tube to the other for lateral passage of a thread into the tube.

4. Thread-guiding means for a sewing machine comprising a tube having in its wall a sinuous slot extending from ne end of the tube to the other for lateral passage of a thread into the tube.

5. Thread-guiding means for a sewing machine comprising a tube, having top and'bottom walls and two side walls, with a sinuous slot formed in the top wall from one end of the tube to the other and extending successively from adjacent one side wall to adjacent the other side wall, said slot permitting lateral passage of a thread into said tube.

6. A thread-guiding tube. having a sinuous.

posed cornplemental convex and concave portions which, when the .blankis folded longitudinally lie adjacent to but are spaced from each other and provide between them the sinuous slot.

8. A blank for forming a folded thread-guiding tube having a sinuous slot in a wall thereof, comprising a serpentine strip of foldable sheet material, the marginaledges of which are formed as alternately convexand concave curves with the convex and concave curves of one edge-transversely opposite complemental concave and con-' vex curves of the other edge, the curvature of sand blank being so proportioned with respect to the width of the blank that the blank is adapted 7 to be folded lengthwise from end to end a p1urality of times along spaced parallelstraight lines between the concave curves at the opposite sides of the blank to form a slotted tube.

ANDREW B. CLAYTON. 

